The present invention relates to a cordless light irradiation device for the purpose of irradiating visible light or invisible light on a specific location.
In the past, there have been such cordless light irradiation light devices as that disclosed in Japanese Patent Sho 63-501054 as a light irradiation device for polymerization of composite resins for dental repair utilizing a light polymerizing type resin, but when the power source voltage drops, the surface of the resin mass is hardened, but the polymerization rate of the interior becomes insufficient, and the problem of falling out is produced.
Because the power source lamp L lights even if the voltage of the power battery B is low, the cordless light irradiation devices being currently used are structured such that a voltage observation circuit A shown in FIG. 1 is provided in the power source circuit, and switch S, by which the power voltage is supplied to the power source circuit, turns off when the battery voltage has dropped lower than a pre-set threshold voltage.
Moreover, a fan is provided for cooling the light source, but because the battery housing of the handpiece is tightly sealed, it is difficult to dissipate the heat of the battery, and there is the concern that the battery temperature may increase, and the performance of the battery deteriorate.